Various prosthetic mesh materials have been proposed to reinforce the abdominal wall and to close abdominal wall defects in animals (including humans). It has been known to repair hernias and other tissue defects and tears by implanting a sheet of surgical mesh fabric prosthesis that is stitched to the surrounding tissue. Commonly, a flat or three dimensional sheet that is appropriately sized and shaped for the particular repair is introduced to the surgical site through an incision in the skin and/or through a trocar or other tubular surgical device. A three dimensional prosthesis might be formed, for instance, by manufacturing a flat sheet of mesh and then heat forming it into a predetermined shape in a mold or on a mandrill.
Hence, the mesh fabric typically is folded into a cylindrical shape with a relatively narrow diameter in order to pass through the incision or trocar. In one technique using a trocar, for example, the surgeon grasps the mesh with a long-nosed surgical grasper and pushes the grasper and mesh through the trocar into the body leading with the distal end of the grasper and with the mesh trailing behind it and folding up around the long jaws of the grasper. The mesh will inherently fold upon itself to pass through the trocar and then can expand back toward its natural shape once it has passed completely through the trocar. After insertion into the animal's body cavity, the surgeon may need to manipulate the mesh with the grasper or another surgical tool in order to spread it out fully into the proper shape and navigate it to the desired position.
In another technique, the mesh is specifically rolled like a cigar into a small-diameter tube and grasped by a surgical grasper with the leading end of the grasper grasping what will be the leading longitudinal end of the tube of mesh material and the rest of the mesh tube disposed between the long jaws of the grasper tool (or possibly disposed with one jaw of the grasper tool within the rolled up prosthesis and the other jaw outside of the mesh tube). The mesh is passed through the trocar, other surgical instrument, or incision and expanded just as described above.
After the prosthesis is introduced into the body and properly positioned, it is fixed to the tissue over the repair site. Traditionally, the mesh is fixed by suturing. However, more recently, mesh prostheses have been developed with a layer of adhesive disposed on a surface thereof so that the mesh prostheses may be adhered to the tissue, rather than stitched. The adhesive typically is pressure activated (i.e., it will stick upon being pressed firmly against the tissue). In addition, the adhesive may be activated (i.e., become sticky) when it is exposed to moisture. Hence, the mesh is kept dry prior to introduction into the patient's body so that it may be rolled up into a narrow tube (or other low profile shape) without sticking to itself. However, once the prosthesis is introduced into the body, it is likely to become wet, and thus sticky, quickly. Thus, once it is in the body, the surgeon typically must work fast to unfold and properly position the prosthesis.
The elimination of stitching is beneficial in that it simplifies the surgery and saves time. However, in addition to the need to work quickly with such adhesive-based mesh prostheses, the additional layer of adhesive usually makes the overall mesh prosthesis stiffer, especially when it is dry, so that it cannot be rolled up into as small a diameter cylinder as non-adhesive based mesh products. It also makes the prosthesis thicker, further exacerbating the problem of minimizing its insertion profile in order to fit through the cannula of a trocar or an incision.